<?php

/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2011 PHPExcel
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 * @package    PHPExcel_Shared
 * @copyright  Copyright (c) 2006 - 2011 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
 * @version    1.7.6, 2011-02-27
 */


/**
 * PHPExcel_Shared_Date
 *
 * @category   PHPExcel
 * @package    PHPExcel_Shared
 * @copyright  Copyright (c) 2006 - 2011 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Shared_Date
{
    /** constants */
    const CALENDAR_WINDOWS_1900 = 1900;        //    Base date of 1st Jan 1900 = 1.0
    const CALENDAR_MAC_1904 = 1904;            //    Base date of 2nd Jan 1904 = 1.0

    private static $ExcelBaseDate    = self::CALENDAR_WINDOWS_1900;

    public static $dateTimeObjectType    = 'DateTime';


    /**
     * Set the Excel calendar (Windows 1900 or Mac 1904)
     *
     * @param     integer    $baseDate            Excel base date
     * @return     boolean                        Success or failure
     */
    public static function setExcelCalendar($baseDate) {
        if (($baseDate == self::CALENDAR_WINDOWS_1900) ||
            ($baseDate == self::CALENDAR_MAC_1904)) {
            self::$ExcelBaseDate = $baseDate;
            return True;
        }
        return False;
    }    //    function setExcelCalendar()


    /**
     * Return the Excel calendar (Windows 1900 or Mac 1904)
     *
     * @return     integer    $baseDate            Excel base date
     */
    public static function getExcelCalendar() {
        return self::$ExcelBaseDate;
    }    //    function getExcelCalendar()


    /**
     * Convert a date from Excel to PHP
     *
     * @param     long     $dateValue        Excel date/time value
     * @return     long                    PHP serialized date/time
     */
    public static function ExcelToPHP($dateValue = 0) {
        if (self::$ExcelBaseDate == self::CALENDAR_WINDOWS_1900) {
            $myExcelBaseDate = 25569;
            //    Adjust for the spurious 29-Feb-1900 (Day 60)
            if ($dateValue < 60) {
                --$myExcelBaseDate;
            }
        } else {
            $myExcelBaseDate = 24107;
        }

        // Perform conversion
        if ($dateValue >= 1) {
            $utcDays = $dateValue - $myExcelBaseDate;
            $returnValue = round($utcDays * 24 * 60 * 60);
            if (($returnValue <= PHP_INT_MAX) && ($returnValue >= -PHP_INT_MAX)) {
                $returnValue = (integer) $returnValue;
            }
        } else {
            $hours = round($dateValue * 24);
            $mins = round($dateValue * 24 * 60) - round($hours * 60);
            $secs = round($dateValue * 24 * 60 * 60) - round($hours * 60 * 60) - round($mins * 60);
            $returnValue = (integer) gmmktime($hours, $mins, $secs);
        }

        // Return
        return $returnValue;
    }    //    function ExcelToPHP()


    /**
     * Convert a date from Excel to a PHP Date/Time object
     *
     * @param     long     $dateValue        Excel date/time value
     * @return     long                    PHP date/time object
     */
    public static function ExcelToPHPObject($dateValue = 0) {
        $dateTime = self::ExcelToPHP($dateValue);
        $days = floor($dateTime / 86400);
        $time = round((($dateTime / 86400) - $days) * 86400);
        $hours = round($time / 3600);
        $minutes = round($time / 60) - ($hours * 60);
        $seconds = round($time) - ($hours * 3600) - ($minutes * 60);

        $dateObj = date_create('1-Jan-1970+'.$days.' days');
        $dateObj->setTime($hours,$minutes,$seconds);

        return $dateObj;
    }    //    function ExcelToPHPObject()


    /**
     * Convert a date from PHP to Excel
     *
     * @param     mixed        $dateValue    PHP serialized date/time or date object
     * @return     mixed                    Excel date/time value
     *                                        or boolean False on failure
     */
    public static function PHPToExcel($dateValue = 0) {
        $saveTimeZone = date_default_timezone_get();
        date_default_timezone_set('UTC');
        $retValue = False;
        if ((is_object($dateValue)) && ($dateValue instanceof self::$dateTimeObjectType)) {
            $retValue = self::FormattedPHPToExcel( $dateValue->format('Y'), $dateValue->format('m'), $dateValue->format('d'),
                                                   $dateValue->format('H'), $dateValue->format('i'), $dateValue->format('s')
                                                 );
        } elseif (is_numeric($dateValue)) {
            $retValue = self::FormattedPHPToExcel( date('Y',$dateValue), date('m',$dateValue), date('d',$dateValue),
                                                   date('H',$dateValue), date('i',$dateValue), date('s',$dateValue)
                                                 );
        }
        date_default_timezone_set($saveTimeZone);

        return $retValue;
    }    //    function PHPToExcel()


    /**
     * FormattedPHPToExcel
     *
     * @param    long    $year
     * @param    long    $month
     * @param    long    $day
     * @param    long    $hours
     * @param    long    $minutes
     * @param    long    $seconds
     * @return  long                Excel date/time value
     */
    public static function FormattedPHPToExcel($year, $month, $day, $hours=0, $minutes=0, $seconds=0) {
        if (self::$ExcelBaseDate == self::CALENDAR_WINDOWS_1900) {
            //
            //    Fudge factor for the erroneous fact that the year 1900 is treated as a Leap Year in MS Excel
            //    This affects every date following 28th February 1900
            //
            $excel1900isLeapYear = True;
            if (($year == 1900) && ($month <= 2)) { $excel1900isLeapYear = False; }
            $myExcelBaseDate = 2415020;
        } else {
            $myExcelBaseDate = 2416481;
            $excel1900isLeapYear = False;
        }

        //    Julian base date Adjustment
        if ($month > 2) {
            $month = $month - 3;
        } else {
            $month = $month + 9;
            --$year;
        }

        //    Calculate the Julian Date, then subtract the Excel base date (JD 2415020 = 31-Dec-1899 Giving Excel Date of 0)
        $century = substr($year,0,2);
        $decade = substr($year,2,2);
        $excelDate = floor((146097 * $century) / 4) + floor((1461 * $decade) / 4) + floor((153 * $month + 2) / 5) + $day + 1721119 - $myExcelBaseDate + $excel1900isLeapYear;

        $excelTime = (($hours * 3600) + ($minutes * 60) + $seconds) / 86400;

        return (float) $excelDate + $excelTime;
    }    //    function FormattedPHPToExcel()


    /**
     * Is a given cell a date/time?
     *
     * @param     PHPExcel_Cell    $pCell
     * @return     boolean
     */
    public static function isDateTime(PHPExcel_Cell $pCell) {
        return self::isDateTimeFormat($pCell->getParent()->getStyle($pCell->getCoordinate())->getNumberFormat());
    }    //    function isDateTime()


    /**
     * Is a given number format a date/time?
     *
     * @param     PHPExcel_Style_NumberFormat    $pFormat
     * @return     boolean
     */
    public static function isDateTimeFormat(PHPExcel_Style_NumberFormat $pFormat) {
        return self::isDateTimeFormatCode($pFormat->getFormatCode());
    }    //    function isDateTimeFormat()


    private static    $possibleDateFormatCharacters = 'ymdHs';

    /**
     * Is a given number format code a date/time?
     *
     * @param     string    $pFormatCode
     * @return     boolean
     */
    public static function isDateTimeFormatCode($pFormatCode = '') {
        // Switch on formatcode
        switch ($pFormatCode) {
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_YYYYMMDD:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_YYYYMMDD2:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_DDMMYYYY:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_DMYSLASH:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_DMYMINUS:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_DMMINUS:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_MYMINUS:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_DATETIME:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_TIME1:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_TIME2:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_TIME3:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_TIME4:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_TIME5:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_TIME6:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_TIME7:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_TIME8:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_YYYYMMDDSLASH:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_XLSX14:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_XLSX15:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_XLSX16:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_XLSX17:
            case PHPExcel_Style_NumberFormat::FORMAT_DATE_XLSX22:
                return true;
        }

        //    Typically number, currency or accounting (or occasionally fraction) formats
        if ((substr($pFormatCode,0,1) == '_') || (substr($pFormatCode,0,2) == '0 ')) {
            return false;
        }
        // Try checking for any of the date formatting characters that don't appear within square braces
        if (preg_match('/(^|\])[^\[]*['.self::$possibleDateFormatCharacters.']/i',$pFormatCode)) {
            //    We might also have a format mask containing quoted strings...
            //        we don't want to test for any of our characters within the quoted blocks
            if (strpos($pFormatCode,'"') !== false) {
                $i = false;
                foreach(explode('"',$pFormatCode) as $subVal) {
                    //    Only test in alternate array entries (the non-quoted blocks)
                    if (($i = !$i) && (preg_match('/(^|\])[^\[]*['.self::$possibleDateFormatCharacters.']/i',$subVal))) {
                        return true;
                    }
                }
                return false;
            }
            return true;
        }

        // No date...
        return false;
    }    //    function isDateTimeFormatCode()


    /**
     * Convert a date/time string to Excel time
     *
     * @param    string    $dateValue        Examples: '2009-12-31', '2009-12-31 15:59', '2009-12-31 15:59:10'
     * @return    float|false        Excel date/time serial value
     */
    public static function stringToExcel($dateValue = '') {
        if (strlen($dateValue) < 2)
            return false;
        if (!preg_match('/^(\d{1,4}[ \.\/\-][A-Z]{3,9}([ \.\/\-]\d{1,4})?|[A-Z]{3,9}[ \.\/\-]\d{1,4}([ \.\/\-]\d{1,4})?|\d{1,4}[ \.\/\-]\d{1,4}([ \.\/\-]\d{1,4})?)( \d{1,2}:\d{1,2}(:\d{1,2})?)?$/iu', $dateValue))
            return false;

        $dateValueNew = PHPExcel_Calculation_DateTime::DATEVALUE($dateValue);

        if ($dateValueNew === PHPExcel_Calculation_Functions::VALUE()) {
            return false;
        } else {
            if (strpos($dateValue, ':') !== false) {
                $timeValue = PHPExcel_Calculation_DateTime::TIMEVALUE($dateValue);
                if ($timeValue === PHPExcel_Calculation_Functions::VALUE()) {
                    return false;
                }
                $dateValueNew += $timeValue;
            }
            return $dateValueNew;
        }


    }

}
